Background: The properties of natural pigments, such as antioxidants, functional, medical, and nutraceutical, has demonstrated the advantages of these natural compounds over synthetic ones. Some products are accepted only when they are pigmented with natural, food-quality colorants: for example poultry products (manly marigold flower extracts). Carotenoids as β-carotene, β-criptoxanthin and lutein are very attractive as natural food colorants due to their antioxidant and pro-vitamin activities which provide additional value to the target products. Marigold (Tagetes erecta) is an Asteraceous ornamental plant native to Mexico, and it is also important as carotenoids source for industrial and medicinal purposes but nowadays its production is destined manly for ornamental purposes.

Results: Friable callus of T. erecta yellow flower (YF) and white flower (WF) varieties were induced from leaf explants on Murashige and Skoog (MS) medium supplemented with 9.0 µM 4-dichlorophenoxyacetic acid (2,4-D) and 8.8 µM benzyladenine (BA). Callus developed from both varieties were different in pigmentation. Extracts characterization from callus cultures was carried out by high-performance liquid chromatography (HPLC). This analytical process detected several carotenoids; the main pigment in extracts from YF callus were lutein and zeaxanthin, whereas in the extracts of the WF callus the main pigment were lutein, zeaxanthin, β-cryptoxanthin and β-carotene. Callus cultures of T. erecta accumulated pigments even after several rounds of subculture.

Conclusions: WF callus appeared to be a suitable candidate as source of different carotenoids, tested varieties could represent an alternative for further studies about in vitro pigment production.